This invention relates to a vehicle suspension assembly incorporating an air spring that provides an additional spring when combined with an existing leaf spring assembly. More particularly, the invention provides such a suspension assembly that can be used to modify an existing suspension by installation on a vehicle that already has a leaf spring suspension. Alternatively, this suspension assembly can be incorporated in original equipment installations.
There have been suspension systems that have a leaf spring assembly and an air spring. Examples are set forth in Raidel U.S. Pat. No. 3,434,707, 3,510,149 and 3,612,572. However, the prior art systems are not designed to take advantage of a complete leaf spring suspension capable of operation as an independent suspension that is combined with an air suspension.